Self-Aligned Double Patterning With Spatial Atomic Layer Deposition

ABSTRACT

Provided are self-aligned double patterning methods including feature trimming. The SADP process is performed in a single batch processing chamber in which the substrate is laterally moved between sections of the processing chamber separated by gas curtains so that each section independently has a process condition.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.61/926,589, filed Jan. 13, 2014, the entire contents of which are herebyincorporated by reference herein.

BACKGROUND

Embodiments of the present disclosure generally relate to an apparatusfor processing substrates. More particularly, the disclosure relates toself-aligned double patterning processing and a batch processingplatform for performing same.

The process of forming semiconductor devices is commonly conducted insubstrate processing platforms containing multiple chambers. In someinstances, the purpose of a multi-chamber processing platform or clustertool is to perform two or more processes on a substrate sequentially ina controlled environment. In other instances, however, a multiplechamber processing platform may only perform a single processing step onsubstrates; the additional chambers are intended to maximize the rate atwhich substrates are processed by the platform. In the latter case, theprocess performed on substrates is typically a batch process, wherein arelatively large number of substrates, e.g. 25 or 50, are processed in agiven chamber simultaneously. Batch processing is especially beneficialfor processes that are too time-consuming to be performed on individualsubstrates in an economically viable manner, such as for ALD processesand some chemical vapor deposition (CVD) processes.

The effectiveness of a substrate processing platform, or system, isoften quantified by cost of ownership (COO). The COO, while influencedby many factors, is largely affected by the system footprint, i.e., thetotal floor space required to operate the system in a fabrication plant,and system throughput, i.e., the number of substrates processed perhour. Footprint typically includes access areas adjacent the system thatare required for maintenance. Hence, although a substrate processingplatform may be relatively small, if access from all sides is requiredfor operation and maintenance, the system's effective footprint maystill be prohibitively large.

The semiconductor industry's tolerance for process variability continuesto decrease as the size of semiconductor devices shrink. To meet thesetighter process requirements, the industry has developed a host of newprocesses which meet the tighter process window requirements, but theseprocesses often take a longer time to complete. For example, for forminga copper diffusion barrier layer conformally onto the surface of a highaspect ratio, 65 nm or smaller interconnect feature, use an ALD processmay be beneficial. ALD is a variant of CVD that demonstrates superiorstep coverage compared to CVD. ALD is based upon atomic layer epitaxy(ALE) that was originally employed to fabricate electroluminescentdisplays. ALD employs chemisorption to deposit a saturated monolayer ofreactive precursor molecules on a substrate surface. This is achieved bycyclically alternating the pulsing of appropriate reactive precursorsinto a deposition chamber. Each injection of a reactive precursor istypically separated by an inert gas purge to provide a new atomic layerto previous deposited layers to form an uniform material layer on thesurface of a substrate. Cycles of reactive precursor and inert purgegases are repeated to form the material layer to a predeterminedthickness. The biggest drawback with ALD techniques is that thedeposition rate is much lower than typical CVD techniques by at least anorder of magnitude. For example, some ALD processes can require achamber processing time from about 10 to about 200 minutes to deposit ahigh quality layer on the surface of the substrate. In choosing such ALDand epitaxy processes for better device performance, the cost tofabricate devices in a conventional single substrate processing chamberwould increase due to very low substrate processing throughput. Hence,when implementing such processes, a continuous substrate processingapproach is needed to be economically feasible.

There is an ongoing need in the art for apparatus and methods ofuniformly depositing a film on a substrate in an efficient and costeffective manner.

SUMMARY

Embodiments of the disclosure are directed to processing methodscomprising providing a substrate with a first layer and a patternedlayer thereon. Portions of the first layer are exposed through thepatterned layer. The patterned layer comprises at least one featurehaving a top surface and a two vertical faces defining a width. Thevertical faces are substantially perpendicular to the first layer. Thepatterned layer is trimmed to reduce the width of the patterned layer. Aspacer layer is deposited over the first layer and patterned layer sothat the spacer layer forms a film on the portions of the first layerexposed through the patterned layer, the top surface and both verticalfaces of the at least one feature. The spacer layer is etched from thetop surface of the at least one feature and the portions of the firstlayer exposed through the patterned layer.

Additional embodiments of the disclosure are directed to processingmethods comprising placing a substrate having a first layer and apatterned layer thereon into a processing chamber comprising a pluralityof sections. Each section is separated from adjacent sections by a gascurtain. Portions of the first layer are exposed through the patternedlayer. The patterned layer comprises at least one feature having a topsurface and two vertical faces defining a width. The vertical faces aresubstantially perpendicular to the first layer. At least a portion ofthe substrate is exposed to a first process condition to trim thepatterned layer to reduce the width of the patterned layer. Thesubstrate is moved laterally through a gas curtain to a second sectionof the processing chamber. The substrate is exposed to a second processcondition to deposit a spacer layer over the first layer and thepatterned layer so that the spacer layer forms a film on the portions ofthe first layer exposed through the patterned layer, the top surface andboth vertical faces of the at least one feature. The substrate is movedlaterally through a gas curtain to a third section of the processingchamber. The substrate is exposed to a third process condition to etchthe spacer layer from the top surface of the at least one feature andthe portions of the first layer are exposed through the patterned layer.During lateral movement of the substrate, a first portion of thesubstrate is exposed to the first process condition at the same timethat a second portion of the surface is exposed to the second processconditions and an intermediate portion of the substrate is exposed tothe gas curtain.

Further embodiments of the disclosure are directed to processing methodscomprising providing a substrate with a first layer comprising adielectric and a patterned layer thereon. Portions of the first layerare exposed through the patterned layer. The patterned layer comprisesat least one feature having a top surface and a two vertical facesdefining a width in the range of about 200 Å to about 800 Å. Thevertical faces are substantially perpendicular to the first layer. Thepatterned layer is exposed to a plasma to reduce the width of thepatterned layer by an amount greater than about 10 Å so that the trimmedvertical faces are substantially perpendicular to the first layer. Aspacer layer comprising one or more of an oxide, a nitride, anoxynitride or a carbonitride is deposited over the first layer andpatterned layer so that the spacer layer forms a film on the portions ofthe first layer exposed through the patterned layer, the top surface andboth vertical faces of the at least one feature. The spacer layer isetched from the top surface of the at least one feature and the portionsof the first layer are exposed through the patterned layer.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Theappended drawings illustrate only typical embodiments of this disclosureand are therefore not to be considered limiting, for the disclosure mayadmit to other equally effective embodiments.

FIG. 1 is a cross-sectional side view of a spatial atomic layerdeposition chamber in accordance with one or more embodiment of thedisclosure;

FIG. 2 shows a perspective view of a susceptor in accordance with one ormore embodiments of the disclosure;

FIG. 3 shows a schematic of a pie-shaped gas distribution assembly inaccordance with one or more embodiments of the disclosure;

FIG. 4 is a schematic plan view of a substrate processing systemconfigured with four gas distribution assembly units with a loadingstation in accordance with one or more embodiments of the disclosure;

FIG. 5 is a schematic plan view of a substrate processing systemconfigured with three gas distribution assembly units;

FIG. 6 shows a cross-sectional view of a processing chamber inaccordance with one or more embodiments of the disclosure;

FIG. 7 shows a perspective view of a susceptor assembly and gasdistribution assembly units in accordance with one or more embodimentsof the disclosure;

FIG. 8 shows a cross-sectional view of a processing chamber inaccordance with one or more embodiments of the disclosure;

FIG. 9 shows a schematic of a pie-shaped gas distribution assembly inaccordance with one or more embodiments of the disclosure; and

FIGS. 10A-10F are an illustration of a self-aligned double patterningprocess in accordance with one or more embodiment of the disclosure.

DETAILED DESCRIPTION

Embodiments of the disclosure provide substrate processing systems forcontinuous substrate deposition to maximize throughput and improveprocessing efficiency and uniformity. The substrate processing systemscan also be used for pre-deposition and post-deposition substratetreatments. Embodiments of the disclosure are related to apparatus andmethods for increasing deposition uniformity in a batch processor.

Embodiments of the disclosure are related to double patterning processesused for IC device fabrication in the semiconductor industry.Specifically, embodiments of the disclosure relate to self-aligneddouble patterning (SADP) technology, photoresist pattern slimming,spacer deposition and spacer etching. Embodiments of the disclosureprovide processes using a batch processing system in which SADP stepscan be implemented sequentially in a single processing system.

In the batch processing system described, there are multiple gas inletchannels which can be used for introduction of different chemicals orplasma gases. These channels are separated spatially within theprocessing chamber by inert purging gases and/or vacuum pumping holeswhich form a gas curtain. The gas curtain ensures that there is minimalor no mixing of gases from different channels to avoid unwanted gasphase reactions. Wafers moving through these different spatiallyseparated channels get sequential and multiple surface exposures todifferent chemical or plasma environment and thus layer by layer growthin spatial ALD mode or surface etching process become possible. Theinventors have discovered that the three SADP processing steps,photoresist (PR) pattern slimming, ALD spacer deposition and spaceretch, can be implemented in a single processing chamber by differentprocessing techniques.

For the PR pattern slimming process, one or more of the plasma channelscould be used to perform a dry etch. Wafers moving through these plasmachannels get exposed to active etching plasma components, i.e. radicalsor ions. Processing parameters can be adjusted to achieveisotropic/anisotropic PR pattern etching/sliming. Specifically, theplasma channel can be switched to either remote or direct mode; the RFfrequency, if RF plasma being used, could be adjusted; the gap betweenthe wafer surface and the plasma grounding plate can be changed; oxygenplasma can be mixed with one or more inert gases, such as Ar, He, N₂,etc., with different gas compositions; and chamber pressure and wafertemperature (<100° C.) could also be adjusted. By tuning theseparameters, the ion energy, composition/density of ions vs. radicals,lifetime of ions/radicals could be tuned to achieve targetedetching/sliming results. Purging and pumping channels in between theseplasma channels could effectively take away the by-products from etchingprocess and generate fresh etching surface. PR etch amount can beaccurately controlled by the number of plasma exposure times at certainfixed wafer moving speed.

For the low temperature (<100° C.) ALD spacer growth, such as siliconoxide, silicon nitride or silicon carbon nitride, etc., one or morechemical channels plus one or more plasma channels could be used forplasma assisted atomic layer deposition (PEALD) of different spacermaterials. For example, the growth of an oxide spacer can be achieved bysequential exposure to an alkylamino silicon precursor and an oxygenplasma. In another words, the wafer being deposited is moving through aprocessing region with a silicon precursor and a processing region withan O₂ plasma. Due to inert gas purging between these two regions, no gasphase mixing/CVD reaction could impact the ALD film growth.

Because of the ALD signature, the as deposited films show excellentwithin wafer uniformity (<0.5% 1 sigma) and deposition conformality(100%) on 3:1 structure wafers. Additionally, depending on the wafermoving speed, film growth rate can be much faster than traditionaltime-based ALD system. The spacer film thickness can be accuratelycontrolled by the number of cycles of ALD exposures.

The PR etching during the initial spacer layer growth, especially foroxide growth with direct oxygen plasma. The inventors have surprisinglyfound that when using direct plasma, an ion blocker can be used tofilter out the directional ion components from the plasma channel.Therefore, the oxide deposition process becomes completely radicalassisted and the PR etching during oxide film growth could beeffectively reduced.

For certain spacer material deposition, more than one chemical can beused for different chemical/plasma channels. For example, during thedeposition of SiCN, silicon, carbon and nitrogen source(s) could be fedthrough different chemical channels. Similarly, the plasma gases beingused here could be different for different plasma channels to realizedifferent functionalities, such as, radical assisted film growth or ionassisted film treatment. For the spacer etching, which is similar to thePR slimming process, one or more plasma channels could be used. Theplasma conditions and gas compositions being used would be differentbased on the spacer material being deposited from the previous PEALDprocess. For example, for oxide spacer, NF₃ based plasma might be usedfor spacer etching.

As used in this specification and the appended claims, the term“substrate” and “wafer” are used interchangeably, both referring to asurface, or portion of a surface, upon which a process acts. Thoseskilled in the art will understand that reference to a substrate canalso refer to only a portion of the substrate, unless the contextclearly indicates otherwise. For example, in spatially separated ALD,described with respect to FIG. 1, each precursor is delivered to thesubstrate, but any individual precursor stream, at any given time, isonly delivered to a portion of the substrate. Additionally, reference todepositing on a substrate can mean both a bare substrate and a substratewith one or more films or features deposited or formed thereon.

As used in this specification and the appended claims, the terms“reactive gas”, “precursor”, “reactant”, and the like, are usedinterchangeably to mean a gas that includes a species which is reactivein an atomic layer deposition process. For example, a first “reactivegas” may simply adsorb onto the surface of a substrate and be availablefor further chemical reaction with a second reactive gas.

FIG. 1 is a schematic cross-sectional view of a portion of a processingchamber 20 in accordance with one or more embodiments of the disclosure.The processing chamber 20 is generally a sealable enclosure, which isoperated under vacuum, or at least low pressure conditions. The chamber100 includes a gas distribution assembly 30 capable of distributing oneor more gases across the top surface 61 of a substrate 60. The gasdistribution assembly 30 can be any suitable assembly known to thoseskilled in the art, and specific gas distribution assemblies describedshould not be taken as limiting the scope of the disclosure. The outputface of the gas distribution assembly 30 faces the first surface 61 ofthe substrate 60.

Substrates for use with the embodiments of the disclosure can be anysuitable substrate. In some embodiments, the substrate is a rigid,discrete, generally planar substrate. As used in this specification andthe appended claims, the term “discrete” when referring to a substratemeans that the substrate has a fixed dimension. The substrate of one ormore embodiments is a semiconductor substrate, such as a 200 mm or 300mm diameter silicon substrate. In some embodiments, the substrate is oneor more of silicon, silicon germanium, gallium arsenide, galliumnitride, germanium, gallium phosphide, indium phosphide, sapphire orsilicon carbide.

The gas distribution assembly 30 comprises a plurality of gas ports totransmit one or more gas streams to the substrate 60 and a plurality ofvacuum ports disposed between each gas port to transmit the gas streamsout of the processing chamber 20. In the embodiment of FIG. 1, the gasdistribution assembly 30 comprises a first precursor injector 120, asecond precursor injector 130 and a purge gas injector 140. Theinjectors 120, 130, 140 may be controlled by a system computer (notshown), such as a mainframe, or by a chamber-specific controller, suchas a programmable logic controller. The precursor injector 120 injects acontinuous (or pulse) stream of a reactive precursor of compound A intothe processing chamber 20 through a plurality of gas ports 125. Theprecursor injector 130 injects a continuous (or pulse) stream of areactive precursor of compound B into the processing chamber 20 througha plurality of gas ports 135. The purge gas injector 140 injects acontinuous (or pulse) stream of a non-reactive or purge gas into theprocessing chamber 20 through a plurality of gas ports 145. The purgegas removes reactive material and reactive by-products from theprocessing chamber 20. The purge gas is typically an inert gas, such as,nitrogen, argon and helium. Gas ports 145 are disposed in between gasports 125 and gas ports 135 so as to separate the precursor of compoundA from the precursor of compound B, avoiding cross-contamination betweenthe precursors.

In another aspect, a remote plasma source (not shown) may be connectedto the precursor injector 120 and the precursor injector 130 prior toinjecting the precursors into the processing chamber 20. The plasma ofreactive species may be generated by applying an electric field to acompound within the remote plasma source. Any power source that iscapable of activating the intended compounds may be used. For example,power sources using DC, radio frequency (RF), and microwave (MW) baseddischarge techniques may be used. If an RF power source is used, the RFpower source can be either capacitively or inductively coupled. Theactivation may also be generated by a thermally based technique, a gasbreakdown technique, a high energy light source (e.g., UV energy), orexposure to an x-ray source. Exemplary remote plasma sources areavailable from vendors such as MKS Instruments, Inc. and Advanced EnergyIndustries, Inc.

The chamber 100 further includes a pumping system 150 connected to theprocessing chamber 20. The pumping system 150 is generally configured toevacuate the gas streams out of the processing chamber 20 through one ormore vacuum ports 155. The vacuum ports 155 are disposed between eachgas port so as to evacuate the gas streams out of the processing chamber20 after the gas streams react with the substrate surface and to furtherlimit cross-contamination between the precursors.

The chamber 100 includes a plurality of partitions 160 disposed on theprocessing chamber 20 between each port. A lower portion of eachpartition extends close to the first surface 61 of substrate 60, forexample, about 0.5 mm or greater from the first surface 61. In thismanner, the lower portions of the partitions 160 are separated from thesubstrate surface by a distance sufficient to allow the gas streams toflow around the lower portions toward the vacuum ports 155 after the gasstreams react with the substrate surface. Arrows 198 indicate thedirection of the gas streams. Since the partitions 160 operate as aphysical barrier to the gas streams, they also limit cross-contaminationbetween the precursors. The arrangement shown is merely illustrative andshould not be taken as limiting the scope of the disclosure. Thoseskilled in the art will understand that the gas distribution systemshown is merely one possible distribution system and the other types ofshowerheads and gas distribution assemblies may be employed.

Atomic layer deposition systems of this sort (i.e., where multiple gasesare separately flowed toward the substrate at the same time) arereferred to as spatial ALD. In operation, a substrate 60 is delivered(e.g., by a robot) to the processing chamber 20 and can be placed on ashuttle 65 before or after entry into the processing chamber. Theshuttle 65 is moved along the track 70, or some other suitable movementmechanism, through the processing chamber 20, passing beneath (or above)the gas distribution assembly 30. In the embodiment shown in FIG. 1, theshuttle 65 is moved in a linear path through the chamber. FIG. 3, asexplained further below, shows an embodiment in which wafers are movedin a circular path through a carousel processing system.

Referring back to FIG. 1, as the substrate 60 moves through theprocessing chamber 20, the first surface 61 of substrate 60 isrepeatedly exposed to the reactive gas A coming from gas ports 125 andreactive gas B coming from gas ports 135, with the purge gas coming fromgas ports 145 in between. Injection of the purge gas is designed toremove unreacted material from the previous precursor prior to exposingthe substrate surface 110 to the next precursor. After each exposure tothe various gas streams (e.g., the reactive gases or the purge gas), thegas streams are evacuated through the vacuum ports 155 by the pumpingsystem 150. Since a vacuum port may be disposed on both sides of eachgas port, the gas streams are evacuated through the vacuum ports 155 onboth sides. Thus, the gas streams flow from the respective gas portsvertically downward toward the first surface 61 of the substrate 60,across the substrate surface 110 and around the lower portions of thepartitions 160, and finally upward toward the vacuum ports 155. In thismanner, each gas may be uniformly distributed across the substratesurface 110. Arrows 198 indicate the direction of the gas flow.Substrate 60 may also be rotated while being exposed to the various gasstreams. Rotation of the substrate may be useful in preventing theformation of strips in the formed layers. Rotation of the substrate canbe continuous or in discrete steps and can occur while the substrate ispassing beneath the gas distribution assembly 30 or when the substrateis in a region before and/or after the gas distribution assembly 30.

Sufficient space is generally provided after the gas distributionassembly 30 to ensure complete exposure to the last gas port. Once thesubstrate 60 has completely passed beneath the gas distribution assembly30, the first surface 61 has completely been exposed to every gas portin the processing chamber 20. The substrate can then be transported backin the opposite direction or forward. If the substrate 60 moves in theopposite direction, the substrate surface may be exposed again to thereactive gas A, the purge gas, and reactive gas B, in reverse order fromthe first exposure.

The extent to which the substrate surface 110 is exposed to each gas maybe determined by, for example, the flow rates of each gas coming out ofthe gas port and the rate of movement of the substrate 60. In oneembodiment, the flow rates of each gas are controlled so as not toremove adsorbed precursors from the substrate surface 61. The widthbetween each partition, the number of gas ports disposed on theprocessing chamber 20, and the number of times the substrate is passedacross the gas distribution assembly may also determine the extent towhich the substrate surface 61 is exposed to the various gases.Consequently, the quantity and quality of a deposited film may beoptimized by varying the above-referenced factors.

Although description of the process has been made with the gasdistribution assembly 30 directing a flow of gas downward toward asubstrate positioned below the gas distribution assembly, thisorientation is not limiting and can be different. In some embodiments,the gas distribution assembly 30 directs a flow of gas upward toward asubstrate surface. As used in this specification and the appendedclaims, the term “passed across” means that the substrate has been movedfrom one side of the gas distribution assembly to the other side so thatthe entire surface of the substrate is exposed to each gas stream fromthe gas distribution plate. Absent additional description, the term“passed across” does not imply any particular orientation of gasdistribution assemblies, gas flows or substrate positions.

In some embodiments, the shuttle 65 is a susceptor 66 for carrying thesubstrate 60. Generally, the susceptor 66 is a carrier which helps toform a uniform temperature across the substrate. The susceptor 66 ismovable in both directions (left-to-right and right-to-left, relative tothe arrangement of FIG. 1) or in a circular direction (relative to FIG.3). The susceptor 66 has a top surface 67 for carrying the substrate 60.The susceptor 66 may be a heated susceptor so that the substrate 60 maybe heated for processing. As an example, the susceptor 66 may be heatedby radiant heat lamps 90, a heating plate, resistive coils, or otherheating devices, disposed underneath the susceptor 66.

In still another embodiment, the top surface 67 of the susceptor 66includes a recess 68 to accept the substrate 60, as shown in FIG. 2. Thesusceptor 66 is generally thicker than the thickness of the substrate sothat there is susceptor material beneath the substrate. In someembodiments, the recess 68 is sized such that when the substrate 60 isdisposed inside the recess 68, the first surface 61 of substrate 60 islevel with, or substantially coplanar with, the top surface 67 of thesusceptor 66. Stated differently, the recess 68 of some embodiments issized such that when a substrate 60 is disposed therein, the firstsurface 61 of the substrate 60 does not protrude above the top surface67 of the susceptor 66. As used in this specification and the appendedclaims, the term “substantially coplanar” means that the top surface ofthe wafer and the top surface of the susceptor assembly are coplanarwithin ±0.2 mm. In some embodiments, the top surfaces are coplanarwithin ±0.15 mm, ±0.10 mm or ±0.05 mm.

FIG. 1 shows a cross-sectional view of a processing chamber in which theindividual gas ports are shown. This embodiment can be either a linearprocessing system in which the width of the individual gas ports issubstantially the same across the entire width of the gas distributionplate, or a pie-shaped segment in which the individual gas ports changewidth to conform to the pie shape. FIG. 3 shows a portion of apie-shaped gas distribution assembly 30. A substrate would be passedacross this gas distribution assembly 30 in an arc shape path 32. Eachof the individual gas ports 125, 135, 145, 155 have a narrower widthnear the inner peripheral edge 33 of the gas distribution assembly 30 aand a larger width near the outer peripheral edge 34 of the gasdistribution assembly 30. The shape or aspect ratio of the individualports can be proportional to, or different from, the shape or aspectratio of the gas distribution assembly 30 segment. In some embodiments,the individual ports are shaped so that each point of a wafer passingacross the gas distribution assembly 30 following path 32 would haveabout the same residence time under each gas port. The path of thesubstrates can be perpendicular to the gas ports. In some embodiments,each of the gas distribution assemblies comprises a plurality ofelongate gas ports which extend in a direction substantiallyperpendicular to the path traversed by a substrate. As used in thisspecification and the appended claims, the term “substantiallyperpendicular” means that the general direction of movement isapproximately perpendicular to the axis of the gas ports. For apie-shaped gas port, the axis of the gas port can be considered to be aline defined as the mid-point of the width of the port extending alongthe length of the port. As described further below, each of theindividual pie-shaped segments can be configured to deliver a singlereactive gas or multiple reactive gases separated spatially or incombination (e.g., as in a typical CVD process).

Processing chambers having multiple gas injectors can be used to processmultiple wafers simultaneously so that the wafers experience the sameprocess flow. For example, as shown in FIG. 4, the processing chamber100 has four gas distribution assemblies 30 and four substrates 60. Atthe outset of processing, the substrates 60 can be positioned betweenthe gas distribution assemblies 30. Rotating the susceptor 66 of thecarousel by 45° will result in each substrate 60 being moved to a gasdistribution assembly 30 (also referred to as an injector assembly) forfilm deposition. This is the position shown in FIG. 4. An additional 45°rotation would move the substrates 60 away from the gas distributionassemblies 30. With spatial ALD injectors, a film is deposited on thewafer during movement of the wafer relative to the injector assembly. Insome embodiments, the susceptor 66 is rotated so that the substrates 60do not stop beneath the gas distribution assemblies 30. The number ofsubstrates 60 and gas distribution assemblies 30 can be the same ordifferent. In some embodiments, there is the same number of wafers beingprocessed as there are gas distribution assemblies. In one or moreembodiments, the number of wafers being processed are an integermultiple of the number of gas distribution assemblies. For example, ifthere are four gas distribution assemblies, there are 4× wafers beingprocessed, where × is an integer value greater than or equal to one.

The processing chamber 100 shown in FIG. 4 is merely representative ofone possible configuration and should not be taken as limiting the scopeof the disclosure. Here, the processing chamber 100 includes a pluralityof gas distribution assemblies 30. In the embodiment shown, there arefour gas distribution assemblies 30 evenly spaced about the processingchamber 100. The processing chamber 100 shown is octagonal, however,those skilled in the art will understand that this is one possible shapeand should not be taken as limiting the scope of the disclosure. The gasdistribution assemblies 30 shown are rectangular, but those skilled inthe art will understand that the gas distribution assemblies can bepie-shaped segments, like that shown in FIG. 3. Additionally, eachsegment can be configured to deliver gases in a spatial type arrangementwith multiple different reactive gases flowing from the same segment orconfigured to deliver a single reactive gas or a mixture of reactivegases.

The processing chamber 100 includes a substrate support apparatus, shownas a round susceptor 66 or susceptor assembly. The substrate supportapparatus, or susceptor 66, is capable of moving a plurality ofsubstrates 60 beneath each of the gas distribution assemblies 30. A loadlock 82 might be connected to a side of the processing chamber 100 toallow the substrates 60 to be loaded/unloaded from the chamber 100.

The processing chamber 100 may include a plurality, or set, of firsttreatment stations 80 positioned between any or each of the plurality ofgas distribution assemblies 30. In some embodiments, each of the firsttreatment stations 80 provides the same treatment to a substrate 60.

The number of treatment stations and the number of different types oftreatment stations can vary depending on the process. For example, therecan be one, two, three, four, five, six, seven or more treatmentstations positioned between the gas distribution assemblies 30. Eachtreatment stations can independently provide a different treatment fromevery other set of treatments station, or there can be a mixture of thesame type and different types of treatments. In some embodiments, one ormore of the individual treatments stations provides a differenttreatment than one or more of the other individual treatment stations.The embodiment shown in FIG. 4 shows four gas distribution assemblieswith spaces between which can include some type of treatment station.However, the processing chamber can readily be incorporated with eightgas distribution assemblies with the gas curtains between.

In the embodiment shown in FIG. 5, a set of second treatment stations 85are positioned between the first treatment stations 80 and the gasdistribution assemblies 30 so that a substrate 60 rotated through theprocessing chamber 100 would encounter, depending on where the substrate60 starts, a gas distribution assembly 30, a first treatment station 80and a second treatment station 85 before encountering a second of any ofthese. For example, as shown in FIG. 5, if the substrate started at thefirst treatment station 80, the substrate would be exposed to, in order,the first treatment station 80, a gas distribution assembly 30 and asecond treatment station 85 before encountering another first treatmentstation 85.

Treatment stations can provide any suitable type of treatment to thesubstrate, film on the substrate or susceptor assembly. For example, UVlamps, flash lamps, plasma sources and heaters. The wafers are thenmoved between positions with the gas distribution assemblies 30 to aposition with, for example, a showerhead delivering plasma to the wafer.The plasma station being referred to as a treatment station 80. In oneor more example, silicon nitride films can be formed with plasmatreatment after each deposition layer. As the ALD reaction is,theoretically, self-limiting as long as the surface is saturated,additional exposure to the deposition gas will not cause damage to thefilm.

Rotation of the carousel can be continuous or discontinuous. Incontinuous processing, the wafers are constantly rotating so that theyare exposed to each of the injectors in turn. In discontinuousprocessing, the wafers can be moved to the injector region and stopped,and then to the region 84 between the injectors and stopped. Forexample, the carousel can rotate so that the wafers move from aninter-injector region across the injector (or stop adjacent theinjector) and on to the next inter-injector region where rotation canpause again. Pausing between the injectors may provide time foradditional processing between each layer deposition (e.g., exposure toplasma).

In some embodiments, the processing chamber comprises a plurality of gascurtains 40. Each gas curtain 40 creates a barrier to prevent, orminimize, the movement of processing gases from the gas distributionassemblies 30 from migrating from the gas distribution assembly regionsand gases from the treatment stations 80 from migrating from thetreatment station regions. The gas curtain 40 can include any suitablecombination of gas and vacuum streams which can isolate the individualprocessing sections from the adjacent sections. In some embodiments, thegas curtain 40 is a purge (or inert) gas stream. In one or moreembodiments, the gas curtain 40 is a vacuum stream that removes gasesfrom the processing chamber. In some embodiments, the gas curtain 40 isa combination of purge gas and vacuum streams so that there are, inorder, a purge gas stream, a vacuum stream and a purge gas stream. Inone or more embodiments, the gas curtain 40 is a combination of vacuumstreams and purge gas streams so that there are, in order, a vacuumstream, a purge gas stream and a vacuum stream. The gas curtains 40shown in FIG. 4 are positioned between each of the gas distributionassemblies 30 and treatment stations 80, however, the curtains can bepositioned at any point or points along the processing path.

FIG. 6 shows an embodiment of a processing chamber 200 including a gasdistribution assembly 220, also referred to as the injectors, and asusceptor assembly 230. In this embodiment, the susceptor assembly 230is a rigid body. The rigid body of some embodiments has a drooptolerance no larger than 0.05 mm. Actuators 232 are placed, for example,at three locations at the outer diameter region of the susceptorassembly 230. As used in this specification and the appended claims, theterms “outer diameter” and “inner diameter” refer to regions near theouter peripheral edge and the inner edge, respectively. The outerdiameter is not to a specific position at the extreme outer edge (e.g.,near shaft 240) of the susceptor assembly 230, but is a region near theouter edge 231 of the susceptor assembly 230. This can be seen in FIG. 6from the placement of the actuators 232. The number of actuators 232 canvary from one to any number that will fit within the physical spaceavailable. Some embodiments have two, three, four or five sets ofactuators 232 positioned in the outer diameter region 231. As used inthis specification and the appended claims, the term “actuator” refersto any single or multi-component mechanism which is capable of movingthe at least a portion of the susceptor assembly toward or away from thegas distribution assembly 220. For example, actuators 232 can be used toensure that the susceptor assembly 230 is substantially parallel to theinjector assembly 220. As used in this specification and the appendedclaims, the term “substantially parallel” used in this regard means thatthe parallelism of the components does not vary by more than 5% relativeto the distance between the components.

Once pressure is applied to the susceptor assembly 230 from theactuators 232, the susceptor assembly 230 can be levelled. As thepressure is applied by the actuators 232, the gap 210 distance can beset to be within the range of about 0.1 mm to about 2.0 mm, or in therange of about 0.2 mm to about 1.8 mm, or in the range of about 0.3 mmto about 1.7 mm, or in the range of about 0.4 mm to about 1.6 mm, or inthe range of about 0.5 mm to about 1.5 mm, or in the range of about 0.6mm to about 1.4 mm, or in the range of about 0.7 mm to about 1.3 mm, orin the range of about 0.8 mm to about 1.2 mm, or in the range of about0.9 mm to about 1.1 mm, or about 1 mm.

The susceptor assembly 230 is positioned beneath the gas distributionassembly 220. The susceptor assembly 230 includes a top surface 241 and,optionally, at least one recess 243 in the top surface 241. The recess243 can be any suitable shape and size depending on the shape and sizeof the wafers 260 being processed. In the embodiment shown, the recess241 has a step region around the outer peripheral edge of the recess243. The steps can be sized to support the outer peripheral edge of thewafer 260. The amount of the outer peripheral edge of the wafer 260 thatis supported by the steps can vary depending on, for example, thethickness of the wafer and the presence of features already present onthe back side of the wafer.

In some embodiments, as shown in FIG. 6, the recess 243 in the topsurface 241 of the susceptor assembly 230 is sized so that a wafer 260supported in the recess 243 has a top surface 261 substantially coplanarwith the top surface 241 of the susceptor assembly 230. As used in thisspecification and the appended claims, the term “substantially coplanar”means that the top surface of the wafer and the top surface of thesusceptor assembly are coplanar within ±0.2 mm. In some embodiments, thetop surfaces are coplanar within ±0.15 mm, ±0.10 mm or ±0.05 mm.

The susceptor assembly 230 of FIG. 6 includes a support post 240 whichis capable of lifting, lowering and rotating the susceptor assembly 230.The susceptor assembly 230 may include a heater, or gas lines, orelectrical components within the center of the support post 240. Thesupport post 240 may be the primary means of increasing or decreasingthe gap between the susceptor assembly 230 and the gas distributionassembly 220, moving the susceptor assembly 230 into rough position. Theactuators 232 can then make micro-adjustments to the position of thesusceptor assembly to create the predetermined gap.

The processing chamber 100 shown in FIG. 6 is a carousel-type chamber inwhich the susceptor assembly 230 can hold a plurality of wafers 260. Thegas distribution assembly 220 may include a plurality of separateinjector units 221, each injector unit 221 being capable of depositing afilm or part of a film on the wafer 260, as the wafer is moved beneaththe injector unit 221. FIG. 7 shows a perspective view of acarousel-type processing chamber 200. Two pie-shaped injector units 221are shown positioned on approximately opposite sides of and above thesusceptor assembly 230. This number of injector units 221 is shown forillustrative purposes only. However, more or less injector units 221 canbe included. In some embodiments, there are a sufficient number ofpie-shaped injector units 221 to form a shape conforming to the shape ofthe susceptor assembly 230. In some embodiments, each of the individualpie-shaped injector units 221 may be independently moved, removed and/orreplaced without affecting any of the other injector units 221. Forexample, one segment may be raised to permit a robot to access theregion between the susceptor assembly 230 and gas distribution assembly220 to load/unload wafers 260.

FIG. 8 shows another embodiment of the disclosure in which the susceptorassembly 230 is not a rigid body. In some embodiments, the susceptorassembly 230 has a droop tolerance of not more than about 0.1 mm, or notmore than about 0.05 mm, or not more than about 0.025 mm, or not morethan about 0.01 mm. Here, there are actuators 232 placed at the outerdiameter region 231 and at the inner diameter region 239 of thesusceptor assembly 230. The actuators 232 can be positioned at anysuitable number of places around the inner and outer periphery of thesusceptor assembly 230. In some embodiments, the actuators 232 areplaced at three locations at both the outer diameter region 231 and theinner diameter region 239. The actuators 232 at both the outer diameterregion 231 and the inner diameter region 239 apply pressure to thesusceptor assembly 230.

FIG. 9 shows an embodiment of a processing chamber comprising a circulargas distribution assembly with a diverter and a susceptor assembly. Thecircular gas distribution assembly 220, a portion of which can be seenin FIG. 9 is positioned within the processing chamber and comprises aplurality of elongate gas ports 125, 135, 145 in a front face 225 of thegas distribution assembly 220. The plurality of elongate gas ports 125,135, 145 extend from an area adjacent the inner peripheral edge 227toward an area adjacent the outer peripheral edge 228 of the gasdistribution assembly 220. The plurality of gas ports shown in FIG. 9include a first reactive gas port 125, a second reactive gas port 135, apurge gas port 145 which surrounds each of the first reactive gas portsand the second reactive gas ports and vacuum ports 155.

A susceptor assembly 230 is positioned within the processing chamber torotate at least one substrate in a substantially circular path about arotational axis. As used in this specification and the appended claims,the term “substantially circular” means that the path is intended to becircular if the substrate were to complete a full rotation. Thesusceptor assembly has a top surface 241 (as shown in FIG. 8) defined byan inner peripheral edge 229 and an outer peripheral edge 231. Thesusceptor assembly 230 is positioned below the gas distribution assembly220 so that the top surface 241 of the susceptor assembly 230 faces thefront face 225 of the gas distribution assembly 220.

Some embodiments of the disclosure are directed to methods of processinga substrate. A substrate is placed into a processing chamber which has aplurality of sections, with each section separated from adjacentsections by a gas curtain. As used in this specification and theappended claims, the terms “section”, “region” and “sector” are usedinterchangeably to describe an area within a batch processing chamber.For example, the component shown in FIG. 9 has two sections. Uponentering the processing chamber, the substrate (also called a wafer) canbe in any of the individual sections. Each section can have the same ordifferent processing conditions from the adjacent sections. As used inthis specification and the appended claims, the term “processingcondition” means the entirety of the conditions within the individualsection. For example, processing conditions include, but are not limitedto, gas composition, pressure, flow rate, temperature and plasma.Processing conditions can be configured to, for example, deposition,etching and treatment (e.g., densification, annealing).

In the first section, the substrate, or a portion of the substrate, isexposed to a first process condition to deposit a first film on thesurface of the substrate. The substrate surface can be a bare substratesurface or any layer previously deposited on the surface. For example,the surface may have a mixed composition with one part being a metal andthe other a dielectric. The individual surface composition can vary andshould not be taken as limiting the scope of the disclosure. The firstprocess conditions in the first section comprise one or more of atemperature change or a first reactive gas. As used in thisspecification and the appended claims, the use of the first reactive gasin the first process conditions, as well as other sections of theprocessing chamber, means the composition, pressure, flow rates, directplasma, remote plasma and combinations thereof of the reactive gas.

Any of the films deposited or formed can be a complete film, such as ametal or dielectric film, or can be a partial film as in the first halfof a two-step reaction. An example of a partial film would be thechemisorption of a compound to a substrate surface that will later bereduced or oxidized to produce the final film. The first film can bepart of an atomic layer deposition process in which the first film is apartial or complete film or part of a chemical vapor deposition process.In a CVD process, the first process conditions may include a mixture ofreactive gases which react in the gas phase to create an activatedspecies which then deposits onto the substrate surface. In someprocesses, the film formed in a section has improved qualities than thefilm entering the section. For example, a film formed in the thirdsection may be exposed to a densification process in the fourth section.The film formed can be from chemical, physical or a combination ofprocesses.

After formation of the first film, the substrate is laterally movedthrough a gas curtain to a second section of the processing chamber. Inthe second section, the first film is exposed to second processconditions to form a second film. The second process conditions compriseone or more of temperature change or a second reactive gas to form thesecond film. The second film can be a different composition than thefirst film, as in the second half of a two-part reaction or a filmhaving a completely different composition, as in a mixed film.

During the movement from the first section to the second section, thesubstrate is exposed to the first process conditions, the second processconditions and a gas curtain which separates the two. The gas curtaincan be, for example, a combination of inert gases and vacuum to ensurethat there is minimal, if any, gas phase reaction between the firstprocess conditions and the second process conditions. At some timeduring the movement, part of the surface is exposed to the first processconditions, another part of the surface is exposed to the second processconditions and an intermediate portion, between the other two portions,of the substrate is exposed to the gas curtain.

Each of the first process conditions, second process conditions and anyother process conditions are selected from the group consisting of asingle reactive gas comprising the first reactive gas, a mixture ofreactive gases comprising the first reactive gas, a remote plasmacomprising the first reactive gas, a direct plasma comprising the firstreactive gas, temperature change and combinations thereof. As used inthis specification and the appended claims, the term “direct plasma”means a plasma that is ignited within the processing chamber. The term“remote plasma” means a plasma that is ignited outside of the processingchamber and flowed into the processing chamber.

The exposure to the first process conditions and the second processconditions can be repeated sequentially to grow a film of predeterminedthickness. For example, the batch processing chamber may contain twosections with the first process conditions and two sections of thesecond process conditions in alternating pattern, so that rotation ofthe substrate around the central axis of the processing chamber causesthe surface to be sequentially and repeatedly exposed to the first andsecond process conditions so that each exposure causes the filmthickness (for depositions) to grow.

FIGS. 10A through 1OF show a typical self-aligned double patterning(SADP) process in accordance with one or more embodiments of thedisclosure. The process shown and described an be performed with anysuitable oxides, dielectrics, photoresists and/or metal layers. In FIG.10A, a substrate 900 is layered with a dielectric 910 and patterned witha photoresist 920. Although dielectric 910 is shown deposited on thesubstrate 900 with a photoresist 920 thereon, those skilled in the artwill understand that there can be intervening layers between thesubstrate 900 and the dielectric 910, or layers between the dielectric910 and the photoresist 920. Additionally, the dielectric 910 layer canbe a different material (e.g., a metal layer).

As shown in FIG. 10B, the photoresist 920 can be exposed to a plasma toetch the sides 921 of the photoresist. By etching the sides of thephotoresist 920, the width of the photoresist is decreased resulting ina slimmer photoresist and a larger area of dielectric 910 exposed. Thisprocess is referred to as photoresist slimming or PR slimming.

As shown in FIG. 10C, a spacer film 930 is deposited over the exposedsurface of the dielectric 910 and the photoresist 920 so that the top922 and sides 921 of the photoresist 920 are conformally coated with thespacer film 930. The spacer film can be made from any suitable materialincluding, but not limited to, an oxide film.

In FIG. 10D, the spacer film 930 has been etched from horizontalsurfaces. This means that the top 922 of the photoresist 920 is exposedand part of the dielectric 910 surface is exposed. In FIG. 10E, theoriginal patterned photoresist 920 is etched away, leaving only what isleft of spacer film 930. The substrate 900 can be etched using thespacers as a guide, and the remaining dielectric 910 and spacer film 930stripped to provide the etched substrate 900 in FIG. 10F. Theselectivity between the films described herein, such as the dielectric,allows for this process to be carried out. If there is insufficientselectivity, a cap, such as SiON, can be placed on the photoresist priorto the deposition of the spacer film. These caps prevent unintentionallyetching away patterned photoresist.

Accordingly, with reference to FIGS. 10A to 10F, one or more embodimentsof the disclosure are directed to processing methods. A substrate 900 isprovided which has a first layer, which may be dielectric 910, and apatterned layer, which may be photoresist 920. Although the first layerdoes not need to be a dielectric and the patterned layer does not needto be a photoresist, these terms are used for convenience ofdescription. Portions of the first layer are exposed through thepatterned layer so that when looking down at the substrate, both thefirst layer and the patterned layer are visible at the same time.

The patterned layer comprises at least one feature having a top surface922 and two sides 921 (i.e., the vertical faces) defining a width W₁.The width W₁ can be any suitable width for a patterned layer. In someembodiments, the width of the at least one feature is in the range ofabout 200 Å to about 800 Å, or in the range of about 300 Å to about 700Å or in the range of about 400 Å to about 600 Å.

The feature or features present on the substrate can be made by anysuitable technique and may be formed prior to placing the substratewithin the processing chamber. In some embodiments, the features areformed within the same processing chamber and the SADP processing. Thefeatures can be any suitable size and any suitable aspect ratio. In someembodiments the aspect ratio of the feature is greater than about 1:1,2:1, 3:1, 4:1 or 5:1. In some embodiments, the feature has an aspectratio in the range of about 1:1 to about 20:1, or in the range of about2:1 to about 15:1, or in the range of about 3:1 to about 10:1, or in therange of about 4:1 to about 8:1.

The vertical faces 921 of the feature are substantially perpendicular tothe first layer. As used in this specification and the appended claims,the term “substantially perpendicular” means that the vertical facesform an angle relative to the first layer in the range of about 80° toabout 100°, or in the range of about 85° to about 95°, or in the rangeof about 88° to about 92°.

The patterned layer can be any suitable material depending on the use ofthe patterned layer. In the example shown in FIGS. 10A through 10F, aself-aligned double patterning procedure is described in which thepatterned layer is one or more of a photoresist or spin-on-carbon.

The patterned layer (e.g., photoresist 920) is exposed to processingconditions to reduce the width of the patterned layer from W₁ to W₂.Accordingly, width W₂ is less than width W₁. In some embodiments, toreduce the width of the patterned layer, trimming is done by exposingthe patterned layer to a plasma. The plasma can be any suitable plasmaincluding, but not limited to, hydrogen, nitrogen, oxygen, argon, carbondioxide and helium. In some embodiments, the patterned layer comprisesspin-on-carbon and the plasma comprises argon and carbon dioxide.

The amount of material removed from the sides of the feature can becontrolled by the amount of exposure to the plasma. In some embodiments,the patterned layer width is reduced by an amount in the range of about10 Å to about 200 Å, or in the range of about 20 Å to about 150 Å, or inthe range of about 30 Å to about 100 Å. In one or more embodiments, thepatterned layer width is reduced by an amount greater than about 10%,15%, 20%, 25%, 30%, 35%, 40%, 45% or 50% of the initial width. The widthof the feature has been slimmed while not being reduced to zero, meaningthat there is some usable feature remaining. After trimming the feature,the vertical faces remain substantially perpendicular to the firstlayer.

Referring to FIG. 10C, a spacer layer (e.g., an oxide film 930) isdeposited over the first layer and patterned layer so that the spacerlayer forms a film on the portions of the first layer exposed throughthe patterned layer, the top surface and both vertical faces of the atleast one feature. The spacer layer deposited can be substantiallyconformal, meaning that the thickness of the spacer layer is uniformacross the horizontal and vertical surfaces. As used in thisspecification and the appended claims, the term “substantiallyconformal” means that the thickness of the film does not vary by morethan about 20%, 15%, 10% or 5% relative to the average film thickness.The spacer layer can be made from any suitable material including, butnot limited to, oxides, nitrides, silicides, oxynitrides, carbonitridesand combinations thereof.

Referring to FIG. 10D, the spacer layer is etched from the horizontalsurfaces, leaving the spacer layer on the vertical faces. Here, the topsurface of the feature and the horizontal portions between features isetched, exposing the top surface of the feature and first layer.

The individual processes can be performed in separate processingchambers or a single processing chamber as described herein. In someembodiments, each process occurs in a single processing chamber in whichthe substrate is moved laterally between a plurality of sections, eachsection separated from adjacent sections by a gas curtain. Inembodiments of this sort, trimming the patterned layer occurs in a firstsection of the processing chamber, depositing the spacer layer occurs ina second section of the processing chamber and etching the spacer layeroccurs in a third section of the processing chamber. For example, aprocessing method of this sort can comprise placing the substrate into aprocessing chamber comprising a plurality of sections, each sectionseparated from adjacent sections by a gas curtain. At least a portion ofthe substrate is exposed to a first process condition to trim thepatterned layer to reduce the width of the patterned layer. Thesubstrate is laterally moved through a gas curtain to a second sectionof the processing chamber. In the second section of the processingchamber, at least a portion of the substrate is exposed to a secondprocess condition to deposit the spacer layer over the first layer andthe patterned layer. The substrate is then laterally moved through a gascurtain to a third section of the processing chamber. At least a portionof the substrate is then exposed to a third process condition to etchthe spacer layer from the top surface of the at least one feature andthe portions of the first layer exposed through the patterned layer.During lateral movement of the substrate from the first section to thesecond section, a first portion of the substrate is exposed to the firstprocess condition at the same time that a second portion of the surfaceis exposed to the second process conditions and an intermediate portionof the substrate is exposed to the gas curtain. The intermediate portionbeing some portion of the substrate between the first portion and thesecond portion. During lateral movement of the substrate from the secondsection to the third section, a first portion of the substrate isexposed to the second process condition at the same time that a secondportion of the substrate is exposed to the third process condition andan intermediate portion of the substrate is exposed to the gas curtain.

FIGS. 10E and 1OF show additional process stages which may be performedin the same processing chamber or different environments. In FIG. 10E,the patterned layer is removed. This process may be referred to as “coreremoval” and is often, but not required to be, done by wet chemicalmethods. In FIG. 10F, the remaining spacer layer and exposed portions ofthe first layer are etched away from the substrate.

In some embodiments, one or more layers may be formed during a plasmaenhanced atomic layer deposition (PEALD) process. In some processes, theuse of plasma provides sufficient energy to promote a species into theexcited state where surface reactions become favorable and likely.Introducing the plasma into the process can be continuous or pulsed. Insome embodiments, sequential pulses of precursors (or reactive gases)and plasma are used to process a layer. In some embodiments, thereagents may be ionized either locally (i.e., within the processingarea) or remotely (i.e., outside the processing area). In someembodiments, remote ionization can occur upstream of the depositionchamber such that ions or other energetic or light emitting species arenot in direct contact with the depositing film. In some PEALD processes,the plasma is generated external from the processing chamber, such as bya remote plasma generator system. The plasma may be generated via anysuitable plasma generation process or technique known to those skilledin the art. For example, plasma may be generated by one or more of amicrowave (MW) frequency generator or a radio frequency (RF) generator.The frequency of the plasma may be tuned depending on the specificreactive species being used. Suitable frequencies include, but are notlimited to, 2 MHz, 13.56 MHz, 40 MHz, 60 MHz and 100 MHz. Althoughplasmas may be used during the deposition processes disclosed herein,plasmas may not be required. Indeed, other embodiments relate todeposition processes under very mild conditions without a plasma.

According to one or more embodiments, the substrate is subjected toprocessing prior to and/or after forming the layer. This processing canbe performed in the same chamber or in one or more separate processingchambers. In some embodiments, the substrate is moved from the firstchamber to a separate, second chamber for further processing. Thesubstrate can be moved directly from the first chamber to the separateprocessing chamber, or the substrate can be moved from the first chamberto one or more transfer chambers, and then moved to the separateprocessing chamber. Accordingly, the processing apparatus may comprisemultiple chambers in communication with a transfer station. An apparatusof this sort may be referred to as a “cluster tool” or “clusteredsystem”, and the like.

Generally, a cluster tool is a modular system comprising multiplechambers which perform various functions including substratecenter-finding and orientation, degassing, annealing, deposition and/oretching. According to one or more embodiments, a cluster tool includesat least a first chamber and a central transfer chamber. The centraltransfer chamber may house a robot that can shuttle substrates betweenand among processing chambers and load lock chambers. The transferchamber is typically maintained at a vacuum condition and provides anintermediate stage for shuttling substrates from one chamber to anotherand/or to a load lock chamber positioned at a front end of the clustertool. Two well-known cluster tools which may be adapted for the presentdisclosure are the Centura® and the Endura®, both available from AppliedMaterials, Inc., of Santa Clara, Calif. The details of one suchstaged-vacuum substrate processing apparatus is disclosed in U.S. Pat.No. 5,186,718, entitled “Staged-Vacuum Wafer Processing Apparatus andMethod,” Tepman et al., issued on Feb. 16, 1993. However, the exactarrangement and combination of chambers may be altered for purposes ofperforming specific portions of a process as described herein. Otherprocessing chambers which may be used include, but are not limited to,cyclical layer deposition (CLD), atomic layer deposition (ALD), chemicalvapor deposition (CVD), physical vapor deposition (PVD), etch,pre-clean, chemical clean, thermal treatment such as RTP, plasmanitridation, degas, orientation, hydroxylation and other substrateprocesses. By carrying out processes in a chamber on a cluster tool,surface contamination of the substrate with atmospheric impurities canbe avoided without oxidation prior to depositing a subsequent film.

According to one or more embodiments, the substrate is continuouslyunder vacuum or “load lock” conditions, and is not exposed to ambientair when being moved from one chamber to the next. The transfer chambersare thus under vacuum and are “pumped down” under vacuum pressure. Inertgases may be present in the processing chambers or the transferchambers. In some embodiments, an inert gas is used as a purge gas toremove some or all of the reactants after forming the layer on thesurface of the substrate. According to one or more embodiments, a purgegas is injected at the exit of the deposition chamber to preventreactants from moving from the deposition chamber to the transferchamber and/or additional processing chamber. Thus, the flow of inertgas forms a curtain at the exit of the chamber.

During processing, the substrate can be heated or cooled. Such heatingor cooling can be accomplished by any suitable means including, but notlimited to, changing the temperature of the substrate support (e.g.,susceptor) and flowing heated or cooled gases to the substrate surface.In some embodiments, the substrate support includes a heater/coolerwhich can be controlled to change the substrate temperatureconductively. In one or more embodiments, the gases (either reactivegases or inert gases) being employed are heated or cooled to locallychange the substrate temperature. In some embodiments, a heater/cooleris positioned within the chamber adjacent the substrate surface toconvectively change the substrate temperature.

The substrate can also be stationary or rotated during processing. Arotating substrate can be rotated continuously or in discreet steps. Forexample, a substrate may be rotated throughout the entire process, orthe substrate can be rotated by a small amount between exposure todifferent reactive or purge gases. Rotating the substrate duringprocessing (either continuously or in steps) may help produce a moreuniform deposition or etch by minimizing the effect of, for example,local variability in gas flow geometries.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

What is claimed is:
 1. A processing method comprising: providing asubstrate with a first layer and a patterned layer thereon, portions ofthe first layer exposed through the patterned layer, the patterned layercomprising at least one feature having a top surface and two verticalfaces defining a width, the vertical faces substantially perpendicularto the first layer; trimming the patterned layer to reduce the width ofthe patterned layer; depositing a spacer layer over the first layer andpatterned layer so that the spacer layer forms a film on the portions ofthe first layer exposed through the patterned layer, the top surface andboth vertical faces of the at least one feature; and etching the spacerlayer from the top surface of the at least one feature and the portionsof the first layer exposed through the patterned layer.
 2. Theprocessing method of claim 1, wherein the patterned layer comprises oneor more of a photoresist or spin-on-carbon.
 3. The processing method ofclaim 1, wherein the patterned layer has a width in the range of about200 Å to about 800 Å.
 4. The processing method of claim 1, wherein thepatterned layer comprises a dielectric.
 5. The processing method ofclaim 1, wherein the patterned layer has an aspect ratio in the range ofabout 1:1 to about 20:1.
 6. The processing method of claim 1, whereintrimming the patterned layer comprises exposing the patterned layer to aplasma.
 7. The processing method of claim 6, wherein the patterned layercomprises spin-on-carbon and the plasma comprises argon and carbondioxide.
 8. The processing method of claim 6, wherein trimming thepatterned layer reduced the width by an amount in the range of about 10Å to about 200 Å.
 9. The processing method of claim 6, wherein aftertrimming the patterned layer, the vertical faces are substantiallyperpendicular to the first layer.
 10. The processing method of claim 1,wherein the spacer layer comprises one or more of an oxide, a nitride ora carbonitride.
 11. The processing method of claim 1, wherein each ofthe trimming, depositing and etching occurs in a single processingchamber in which the substrate is moved laterally between a plurality ofsections, each section separated from adjacent sections by a gascurtain.
 12. The processing method of claim 11, wherein trimming thepatterned layer occurs in a first section of the processing chamber,depositing the spacer layer occurs in a second section of the processingchamber and etching the spacer layer occurs in a third section of theprocessing chamber.
 13. The method of claim 12, further comprisingremoving the patterned layer followed by etching the spacer and exposedfirst layer .
 14. A processing method comprising: placing a substratehaving a first layer and a patterned layer thereon into a processingchamber comprising a plurality of sections, each section separated fromadjacent sections by a gas curtain, portions of the first layer exposedthrough the patterned layer, the patterned layer comprising at least onefeature having a top surface and two vertical faces defining a width,the vertical faces substantially perpendicular to the first layer;exposing at least a portion of the substrate to a first processcondition to trim the patterned layer to reduce the width of thepatterned layer; laterally moving the substrate through a gas curtain toa second section of the processing chamber; exposing the substrate to asecond process condition to deposit a spacer layer over the first layerand the patterned layer so that the spacer layer forms a film on theportions of the first layer exposed through the patterned layer, the topsurface and both vertical faces of the at least one feature; laterallymoving the substrate through a gas curtain to a third section of theprocessing chamber; and exposing the substrate to a third processcondition to etch the spacer layer from the top surface of the at leastone feature and the portions of the first layer exposed through thepatterned layer, wherein during lateral movement of the substrate, afirst portion of the substrate is exposed to the first process conditionat the same time that a second portion of the surface is exposed to thesecond process conditions and an intermediate portion of the substrateis exposed to the gas curtain.
 15. The processing method of claim 14,wherein the patterned layer has a width in the range of about 200 Å toabout 800 Å.
 16. The processing method of claim 14, wherein the firstprocess conditions to trim the patterned layer comprises exposing thepatterned layer to a plasma.
 17. The processing method of claim 16,wherein trimming the patterned layer reduced the width by an amount inthe range of about 10 Å to about 200 Å.
 18. The processing method ofclaim 14, wherein the spacer layer comprises one or more of an oxide, anitride or a carbonitride.
 19. The method of claim 14, furthercomprising removing the patterned layer followed by etching the spacerand exposed first layer.
 20. A processing method comprising: providing asubstrate with a first layer comprising a dielectric and a patternedlayer thereon, portions of the first layer exposed through the patternedlayer, the patterned layer comprising at least one feature having a topsurface and a two vertical faces defining a width in the range of about200 Å to about 800 Å, the vertical faces substantially perpendicular tothe first layer; exposing the patterned layer to a plasma to reduce thewidth of the patterned layer by an amount greater than about 10 Å sothat the trimmed vertical faces are substantially perpendicular to thefirst layer; depositing a spacer layer comprising one or more of anoxide, a nitride, an oxynitride or a carbonitride over the first layerand patterned layer so that the spacer layer forms a film on theportions of the first layer exposed through the patterned layer, the topsurface and both vertical faces of the at least one feature; and etchingthe spacer layer from the top surface of the at least one feature andthe portions of the first layer exposed through the patterned layer.